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package com.taobao.android.builder.tools.classinject;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.maven.wagon.PathUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.JarOutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipException;
import java.util.zip.ZipOutputStream;

import javassist.CannotCompileException;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtConstructor;
import javassist.CtField;
import javassist.CtMethod;
import javassist.CtNewMethod;
import javassist.Modifier;
import javassist.NotFoundException;

/**
 * 通过Javassist进行代码注入操作
 * Created by shenghua.nish on 2015-10-22 下午6:35.
 */
public class CodeInjectByJavassist {

    public static Map<String, ClazzInjecter> sInjecterMap = new HashMap<String, ClazzInjecter>();

    private static Logger logger = LoggerFactory.getLogger(CodeInjectByJavassist.class);

    public synchronized static byte[] inject(ClassPool pool,
                                             String className,
                                             InjectParam injectParam) throws Exception {
        try {
            CtClass cc = pool.get(className);
            cc.defrost();
            if (className.equalsIgnoreCase("android.taobao.atlas.framework.FrameworkProperties") ||
                    className.equalsIgnoreCase("android.taobao.atlas.version.VersionKernal")) {

                if (StringUtils.isNotBlank(injectParam.version)) {
                    CtClass ctClass = pool.get("java.lang.String");
                    CtField ctField = new CtField(ctClass, "version", cc);
                    ctField.setModifiers(Modifier.PRIVATE);
                    CtMethod ctMethod = CtNewMethod.getter("getVersion", ctField);
                    ctMethod.setModifiers(Modifier.PUBLIC);
                    CtField.Initializer initializer = CtField.Initializer.constant(injectParam.version);
                    cc.addField(ctField, initializer);
                    cc.addMethod(ctMethod);
                    logger.info(
                            "[android.taobao.atlas.framework.FrameworkProperties] inject version " +
                                    injectParam.version);
                }

                addField(pool, cc, "bundleInfo", injectParam.bundleInfo);
                addField(pool, cc, "autoStartBundles", injectParam.autoStartBundles);
                addField(pool, cc, "preLaunch", injectParam.preLaunch);
                addField(pool, cc, "group", injectParam.group);
                addField(pool, cc, "outApp", String.valueOf(injectParam.outApp));
            }

            ClazzInjecter clazzInjecter = sInjecterMap.get(className);
            if (null != clazzInjecter) {
                Map<String, String> stringMap = clazzInjecter.getInjectFields();
                if (!stringMap.isEmpty()) {
                    for (String key : stringMap.keySet()) {
                        addField(pool, cc, key, stringMap.get(key));
                    }
                }
            }

            if (!injectParam.removePreverify) {
                Collection<String> refClasses = cc.getRefClasses();
                if (refClasses.contains("com.taobao.verify.Verifier")) {
                    return cc.toBytecode();
                }
                boolean flag = false;
                if (className.equalsIgnoreCase("com.ut.mini.crashhandler.IUTCrashCaughtListner")) {
                    flag = true;
                }

                if (cc.isInterface()) {
                    final CtClass defClass = pool.get(Class.class.getName());
                    CtField defField = new CtField(defClass, "_inject_field__", cc);
                    defField.setModifiers(Modifier.STATIC | Modifier.PUBLIC | Modifier.FINAL);
                    cc.addField(defField,
                                CtField.Initializer.byExpr(
                                        "Boolean.TRUE.booleanValue()?java.lang.String.class:com.taobao.verify.Verifier.class;"));
                } else {
                    CtConstructor[] ctConstructors = cc.getDeclaredConstructors();
                    if (null != ctConstructors && ctConstructors.length > 0) {
                        CtConstructor ctConstructor = ctConstructors[0];
                        ctConstructor.insertBeforeBody(
                                "if(Boolean.FALSE.booleanValue()){java.lang.String.valueOf(com.taobao.verify.Verifier.class);}");
                    } else {
                        final CtClass defClass = pool.get(Class.class.getName());
                        CtField defField = new CtField(defClass, "_inject_field__", cc);
                        defField.setModifiers(Modifier.STATIC);
                        cc.addField(defField,
                                    CtField.Initializer.byExpr(
                                            "Boolean.TRUE.booleanValue()?java.lang.String.class:com.taobao.verify.Verifier.class;"));
                    }
                }
            }
            return cc.toBytecode();
        } catch (Throwable e) {
            throw new Exception("[InjectError]:" + className + ",reason:" + e.getMessage());
        }
    }

    private static void addField(ClassPool pool,
                                 CtClass cc,
                                 String key,
                                 String value) throws NotFoundException, CannotCompileException {
        if (StringUtils.isNotBlank(value)) {
            try {
                cc.removeField(cc.getField(key));
            } catch (NotFoundException notfoundException) {
            }
            logger.info("inject key " + key + "->" + value);
            CtClass ctClass = pool.get("java.lang.String");
            CtField ctField = new CtField(ctClass, key, cc);
            ctField.setModifiers(Modifier.STATIC | Modifier.PUBLIC);
            CtField.Initializer initializer = CtField.Initializer.constant(value);
            cc.addField(ctField, initializer);
        }
    }

    /**
     * 对指定的folder中的class文件进行注入替换操作
     *
     * @param pool
     * @param folder
     * @param outFolder
     * @return
     * @throws IOException
     * @throws CannotCompileException
     * @throws NotFoundException
     * @throws Exception
     */
    public static List<String> injectFolder(ClassPool pool,
                                            File folder,
                                            File outFolder,
                                            InjectParam injectParam) {
        List<String> errorFiles = new ArrayList<String>();
        if (folder.exists() && folder.isDirectory()) {
            Collection<File> classFiles = FileUtils.listFiles(folder, new String[]{"class"}, true);
            for (File classFile : classFiles) {
                String className = PathUtils.toRelative(folder, classFile.getAbsolutePath());
                File outClassFile = new File(outFolder, className);
                outClassFile.getParentFile().mkdirs();
                className = StringUtils.replace(className, File.separator, ".");
                className = className.substring(0, className.length() - 6);
                byte[] codes;
                try {
                    codes = inject(pool, className, injectParam);
                    FileUtils.writeByteArrayToFile(outClassFile, codes);
                } catch (Throwable e) {
                    System.err.println(e.getMessage());
                    // 发现异常不做处理，使用原先的类
                    try {
                        FileUtils.copyFile(classFile, outClassFile);
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                }
            }
        }
        return errorFiles;
    }

    /**
     * 对于指定的jar包进行代码的注入
     *
     * @param inJar
     * @param outJar
     * @throws IOException
     * @throws NotFoundException
     * @throws CannotCompileException
     */
    public static List<String> inject(ClassPool pool,
                                      File inJar,
                                      File outJar,
                                      InjectParam injectParam) throws IOException {
        List<String> errorFiles = new ArrayList<String>();
        JarFile jarFile = newJarFile(inJar);

        outJar.getParentFile().mkdirs();
        FileOutputStream fileOutputStream = new FileOutputStream(outJar);
        JarOutputStream jos = new JarOutputStream(new BufferedOutputStream(fileOutputStream));
        Enumeration<JarEntry> jarFileEntries = jarFile.entries();
        JarEntry jarEntry = null;
        while (jarFileEntries.hasMoreElements()) {
            jarEntry = jarFileEntries.nextElement();
            String name = jarEntry.getName();
            String className = StringUtils.replace(name, File.separator, "/");
            className = StringUtils.replace(className, "/", ".");
            className = StringUtils.substring(className, 0, className.length() - 6);
            if (!StringUtils.endsWithIgnoreCase(name, ".class")) {
                InputStream inputStream = jarFile.getInputStream(jarEntry);
                copyStreamToJar(inputStream, jos, name, jarEntry.getTime(), jarEntry);
                IOUtils.closeQuietly(inputStream);
            } else {
                byte[] codes;
                try {
                    codes = inject(pool, className, injectParam);
                    InputStream classInstream = new ByteArrayInputStream(codes);
                    copyStreamToJar(classInstream, jos, name, jarEntry.getTime(), jarEntry);
                } catch (Throwable e) { // 如果出现异常，则原样写入
                    System.err.println(e.getMessage());
                    InputStream inputStream = jarFile.getInputStream(jarEntry);
                    copyStreamToJar(inputStream, jos, name, jarEntry.getTime(), jarEntry);
                    IOUtils.closeQuietly(inputStream);
                    errorFiles.add(className);
                }
            }
        }
        jarFile.close();
        IOUtils.closeQuietly(jos);
        return errorFiles;
    }

    private static void copyStreamToJar(InputStream zin,
                                        ZipOutputStream out,
                                        String currentName,
                                        long fileTime,
                                        ZipEntry zipEntry) throws IOException {
        // Create new entry for zip file.
        ZipEntry newEntry = new ZipEntry(currentName);

        // Make sure there is date and time set.
        if (fileTime != -1) {
            newEntry.setTime(fileTime); // If found set it into output file.
        }
        out.putNextEntry(newEntry);
        if (zin != null) {
            IOUtils.copy(zin, out);
        }
    }

    private static JarFile newJarFile(File jar) throws IOException {
        try {
            return new JarFile(jar);
        } catch (ZipException zex) {
            throw new ZipException("error in opening zip file " + jar);
        }
    }

    public static String toRelative(File basedir, String absolutePath) {
        absolutePath = absolutePath.replace('\\', '/');
        String basedirPath = basedir.getAbsolutePath().replace('\\', '/');
        String relative;
        if (absolutePath.startsWith(basedirPath)) {
            relative = absolutePath.substring(basedirPath.length());
            if (relative.startsWith("/")) {
                relative = relative.substring(1);
            }

            if (relative.length() <= 0) {
                relative = ".";
            }
        } else {
            relative = absolutePath;
        }

        return relative;
    }
}
